Owing to their good light quality and long life, recessed lamps are increasingly widespread in many areas of daily life. Even in applications with high requirements in terms of esthetics and efficiency it has become desirable to replace conventional incandescent lamps operating on the system voltage with halogen incandescent lamps. For these reasons, lamps with inserted halogen incandescent lamps have been developed which are surrounded by an enveloping bulb and, as a result, outwardly barely differ from conventional incandescent lamps for general lighting.
Such a lamp is described, for example, on the Internet domain www.osram.de under the product designation “HALOLUX®T”. With these lamps, a recessed halogen lamp with a pinch seal at one end is inserted into a base via an electrically conducting mounting clip and surrounded by an enveloping bulb. As in the case of conventional incandescent lamps, in the event of a failure of such a halogen incandescent lamp it needs to be completely replaced, i.e. including the base and the enveloping bulb.
Dimmable high-volt halogen incandescent lamps having a long life and a short overall length, as are described, for example, on the Internet domain www.osram.de under the product designation “HALOPIN®”, are permissible for operation in open luminaires, but have a high surface temperature. Owing to this high surface temperature, general use in old luminaires in which, for example, the screw-type lampholder E27 is used, is not recommended. Such high-volt halogen incandescent lamps are designed to have an integrated safety function and have a dedicated base/lampholder system, in the case of the incandescent lamp “HALOPIN®”, a plug-in system with the designation G9. Owing to this plug-in system, it is also not possible to use these high-volt halogen incandescent lamps in screw-type lampholders.
The patent specification U.S. Pat. No. 6,075,318 has disclosed a high-volt halogen incandescent lamp having a lampholder on which a screw base is provided. A first contact to a first power supply to the lamp is in touching contact with the side contact of the screw base, while a second cable extends from a bottom contact of the screw base to a second contact to a second power supply to the lamp. The outer bulb around the halogen incandescent lamp is simply a design feature owing to a projection having the function of protection against electric shock.